U.S. patent application number 12/529707 was filed with the patent office on 2010-05-06 for method for the soldering repair of a component in a vacuum and an adjusted partial oxygen pressure.
This patent application is currently assigned to MTU Aero Engines GmbH. Invention is credited to Paul Heinz, Robert Singer.
Application Number | 20100108745 12/529707 |
Document ID | / |
Family ID | 38294164 |
Filed Date | 2010-05-06 |
United States Patent
Application |
20100108745 |
Kind Code |
A1 |
Heinz; Paul ; et
al. |
May 6, 2010 |
METHOD FOR THE SOLDERING REPAIR OF A COMPONENT IN A VACUUM AND AN
ADJUSTED PARTIAL OXYGEN PRESSURE
Abstract
A method for the repair of a component by a solder is disclosed.
The method is performed under specifically selected vacuum
conditions in order to prevent oxidation and vaporization.
Inventors: |
Heinz; Paul; (Erlangen,
DE) ; Singer; Robert; (Erlangen, DE) |
Correspondence
Address: |
CROWELL & MORING LLP;INTELLECTUAL PROPERTY GROUP
P.O. BOX 14300
WASHINGTON
DC
20044-4300
US
|
Assignee: |
MTU Aero Engines GmbH
Munich
DE
|
Family ID: |
38294164 |
Appl. No.: |
12/529707 |
Filed: |
February 15, 2008 |
PCT Filed: |
February 15, 2008 |
PCT NO: |
PCT/EP08/51829 |
371 Date: |
September 2, 2009 |
Current U.S.
Class: |
228/119 |
Current CPC
Class: |
B23K 1/206 20130101;
Y02T 50/67 20130101; C22C 19/057 20130101; C22C 19/05 20130101;
B23K 2101/001 20180801; B23K 1/008 20130101; F01D 5/005 20130101;
Y10T 29/49318 20150115; F05D 2230/238 20130101; B23K 35/30
20130101; B23K 1/0018 20130101; B23K 35/304 20130101; Y02T 50/60
20130101 |
Class at
Publication: |
228/119 |
International
Class: |
B23K 31/02 20060101
B23K031/02 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 6, 2007 |
EP |
07004599.2 |
Claims
1-16. (canceled)
17. A method for a soldering repair of a component by a solder in a
processing chamber, comprising the steps of: adjusting an oxygen
partial pressure of less than 3.5*10.sup.-6mbar and greater than
10.sup.-7 mbar in the processing chamber; and adjusting a total
pressure of less than 10 mbar and greater than 0.035 mbar in the
processing chamber.
18. The method according to claim 17, wherein prior to a heating of
the component in the processing chamber with the solder a flushing
of the processing chamber with an inert gas is performed.
19. The method according to claim 18, wherein a throughput during
the flushing lies between 0.2 l/min and 1 l/min.
20. The method according to claim 19, wherein the throughput is 1
l/min.
21. The method according to claim 18, wherein an inert gas is
filtered though a gas cleaning cartridge before entering the
processing chamber.
22. The method according to claim 17, wherein the component
features a nickel-based alloy.
23. The method according to claim 17, wherein the soldering is
conducted isothermally.
24. The method according to claim 17, wherein the soldering is
conducted in a temperature-gradient method.
25. The method according to claim 17, wherein the solder is
directionally solidified.
26. The method according to claim 17, wherein the solder is
nickel-based.
27. The method according to claim 26, wherein the solder features
chromium, cobalt and tungsten.
28. The method according to claim 26, wherein the solder contains
zirconium.
29. The method according to claim 26, wherein the solder contains
scandium.
30. The method according to claim 26, wherein the solder contains
zirconium and does not contain any scandium.
31. The method according to claim 26, wherein the solder contains
scandium and does not contain any zirconium.
32. The method according to claim 26, wherein the solder contains
zirconium and scandium.
Description
BACKGROUND AND SUMMARY OF THE INVENTION
[0001] This application claims the priority of International
Application No. PCT/EP2008/051829, filed Feb. 15, 2008, and
European Patent Document No. 07004599.2, filed Mar. 6, 2007, the
disclosures of which are expressly incorporated by reference
herein.
[0002] The invention relates to a method for the soldering repair
of a component in a vacuum.
[0003] Components must sometimes be repaired after manufacturing,
for example, after casting or after they have been in use and have
formed cracks. There are various repair methods for this such as,
for example, the welding method, in which, however, a substrate
material of the component must be co-fused, which can produce
damage in particular to cast and directionally solidified
components, and lead to vaporization of constituents of the
substrate material. A soldering method operates at lower
temperatures as compared to the temperature in the welding method
and thus as compared to the melting temperature of the substrate
material. Despite this, the solder should possess a high strength
so that the crack filled with solder or the depression does not
produce a weakening of the overall component at high operating
temperatures.
[0004] U.S. Pat. Nos. 4,908,185; 5,993,980; 4,913,752; 4,915,903 as
well as U.S. Pat. No. 4,789,412 disclose the addition of
additives.
[0005] Therefore, the objective of the invention is disclosing a
method for repairing a component wherein oxidation and vaporization
are avoided.
[0006] Preferably used solder alloys are disclosed in Application
PCT/EP2006/065753, which is disclosed here only in claim form:
[0007] 1. Solder alloy with a nickel-base, [0008] comprising (in %
by weight), [0009] in particular (in % by weight) [0010] chromium
(Cr), in particular, 7.5% by weight to 11% by weight, [0011] in
particular, preferably 8.5% to 10% Cr, [0012] cobalt (Co), in
particular, 8.0% by weight to 11.4% by weight, [0013] in
particular, preferably 9.0% to 10.4% Co, [0014] tungsten (W), in
particular, 2.8% by weight to 6.9% by weight, [0015] in particular,
preferably 3.8% to 5.9% W, [0016] as well as 2% to 22.4%, in
particular, 3% to 19.4%, [0017] of a melting point reducer, [0018]
which contains at least one element from the group including
scandium (Sc), zirconium (Zr), aluminum (Al), titanium (Ti) and
tantalum (Ta), [0019] optionally up to 1.9% molybdenum (Mo) and
[0020] the remainder nickel (Ni). [0021] 2. Solder alloy according
to Claim 1, [0022] characterized in that [0023] the melting point
reducer is formed from zirconium (Zr). [0024] 3. Solder alloy
according to Claim 1, [0025] characterized in that [0026] the
melting point reducer contains zirconium (Zr). [0027] 4. Solder
alloy according to Claim 1 or 3, [0028] characterized in that
[0029] the melting point reducer is made of zirconium (Zr),
aluminum (Al), titanium (Ti) and tantalum (Ta). [0030] 5. Solder
alloy according to Claim 1 or 3, [0031] characterized in that
[0032] the melting point reducer is made of zirconium (Zr) and two
elements from the group including aluminum (Al), titanium (Ti) and
tantalum (Ta). [0033] 6. Solder alloy according to Claim 1 or 3,
[0034] characterized in that [0035] the melting point reducer is
made of zirconium (Zr) and one of the elements of the group
including aluminum (AU, titanium (Ti) and tantalum (Ta). [0036] 7.
Solder alloy according to Claim 1, [0037] characterized in that
[0038] the melting point reducer is formed from scandium (Sc).
[0039] 8. Solder alloy according to Claim 1, 3 or 7, [0040]
characterized in that [0041] the melting point reducer contains at
least 4% by weight scandium (Sc), in particular, at least 6% by
weight, 8% by weight or 10% by weight. [0042] 9. Solder alloy
according to Claim 1, 3, 5 or 8, [0043] characterized in that
[0044] the melting point reducer includes tantalum (Ta) and
titanium (Ti), in particular, a maximum of 6% by weight
(titanium+tantalum), in particular, 3% by weight tantalum and 3% by
weight titanium. [0045] 10. Solder alloy according to Claim 1, 3, 5
or 8, [0046] characterized in that [0047] the melting point reducer
includes aluminum (Al) and tantalum (Ta), in particular, a maximum
of 6% by weight (aluminum and tantalum), in particular, 3% by
weight aluminum and 3% by weight tantalum. [0048] 11. Solder alloy
according to Claim 1, 3, 5 or 8, [0049] characterized in that
[0050] the melting point reducer includes aluminum (Al) and
titanium (Ti), in particular, a maximum of 6% by weight
(aluminum+titanium), in particular, 3% by weight aluminum and 3% by
weight titanium. [0051] 12. Solder alloy according to Claim 1, 7,
8, 9, 10 or 11, [0052] characterized in that [0053] the melting
point reducer does not contain any zirconium (Zr). [0054] 13.
Solder alloy according to Claim 1, 3, 8 or 12, [0055] characterized
in that [0056] the melting point reducer features the elements
tantalum (Ta), aluminum (Al) and titanium (Ti), in particular, in
equal percentages. [0057] 14. Solder alloy according to Claim 1, 3,
8, 9, 10, 11 or 12, [0058] characterized in that [0059] the melting
point reducer features two of the elements from the group including
tantalum (Ta), aluminum (Al) and titanium (Ti), in particular, a
maximum of 6% by weight, in particular, in equal percentages.
[0060] 15. Solder alloy according to Claim 1, 3, 8 or 12, [0061]
characterized in that [0062] the melting point reducer features one
of the elements from the group including tantalum (Ta), aluminum
(Al) and titanium (Ti), in particular, a maximum of 3% by weight.
[0063] 16. Solder alloy according to Claim 1, 3, 4, 5, 8, 9, 10, 11
or 12, [0064] characterized in that [0065] the melting point
reducer contains a maximum of 9% by weight of at least one of the
elements from the group including tantalum (Ta), aluminum (Al) or
titanium (Ti), in particular, in equal percentages. [0066]
17.Solder alloy according to Claim 1, [0067] characterized in that
[0068] the melting point reducer is made of tantalum (Ta), aluminum
(Al) and titanium (Ti), in particular, in equal percentages. [0069]
18. Solder alloy according to Claim 1, 3, 4, 9, 10, 11, 12, 13, 14,
15 or 16, characterized in that [0070] the melting point reducer
does not contain any scandium (Sc). [0071] 19. Solder alloy
according to Claims 1, 3 to 6, 9 to 11, 13 to 17, [0072]
characterized in that [0073] the melting point reducer contains
aluminum (Al), in particular, 3% by weight Al. [0074] 20. Solder
alloy according to Claims 1, 3, 4, 5, 6, 9 to 18, [0075]
characterized in that [0076] the melting point reducer contains
titanium (Ti), in particular, 3% by weight Ti. [0077] 21. Solder
alloy according to Claims 1, 3, 4, 5, 6, 9 to 18, [0078]
characterized in that [0079] the melting point reducer contains
tantalum (Ta), in particular, 3% by weight Ta. [0080] 22. Solder
alloy according to Claim 1, 3, 8, 12, 14, 15, 18, 19 or 21, [0081]
characterized in that [0082] the melting point reducer does not
contain any titanium (Ti). [0083] 23. Solder alloy according to
Claim 1, 3, 8, 12, 14, 16, 18, 20 or 21, [0084] characterized in
that [0085] the melting point reducer does not contain any
aluminum. [0086] 24. Solder alloy according to Claim 1, 3, 8, 12,
14, 16, 18, 19 or 20, [0087] characterized in that [0088] the
melting point reducer does not contain any tantalum (Ta). [0089]
25. Solder alloy according to Claim 1, 3, 9, 10, 11, 13 ,19, 20 or
21, [0090] characterized in that [0091] the melting point reducer
contains up to 2% by weight scandium (Sc), in particular, 0.5% by
weight scandium. [0092] 26. Solder alloy according to Claim 1, 3 or
18, [0093] characterized in that [0094] the melting point reducer
contains tantalum (Ti) and zirconium (Zr), in particular, 3% by
weight Ti and 3% by weight Zr. [0095] 27. Solder alloy according to
Claim 1, 3 or 18, [0096] characterized in that [0097] the melting
point reducer contains aluminum (Al) and zirconium (Zr), in
particular, with 3% by weight Al. [0098] 28. Solder alloy according
to Claim 1, [0099] characterized in that [0100] the chromium
percentage is 10% by weight. [0101] 29. Solder alloy according to
Claim 1, [0102] characterized in that [0103] the chromium
percentage is 8.5% by weight. [0104] 30. Solder alloy according to
Claim 1, [0105] characterized in that [0106] the cobalt percentage
is 9% by weight. [0107] 31. Solder alloy according to Claim 1,
[0108] characterized in that [0109] der cobalt percentage is 10% by
weight to 11% by weight, in particular, 10.4% by weight. [0110] 32.
Solder alloy according to Claim 1, [0111] characterized in that
[0112] the tungsten percentage is 3.8% by weight. [0113] 33. Solder
alloy according to Claim 1, [0114] characterized in that [0115] the
tungsten percentage is 4.4% by weight. [0116] 34. Solder alloy
according to Claim 1, [0117] characterized in that [0118] the
tungsten percentage is 5.9% by weight. [0119] 35. Solder alloy
according to Claim 1, [0120] characterized in that [0121] the alloy
contains molybdenum, in particular, 1.9% by weight. [0122] 36.
Solder alloy according to Claim 1, [0123] characterized in that
[0124] the alloy does not contain any molybdenum. [0125] 37. Solder
alloy according to Claim 1 or 8, [0126] characterized in that
[0127] the melting point reducer contains 6% by weight scandium.
[0128] 38. Solder alloy according to Claim 1 or 8, [0129]
characterized in that [0130] the melting point reducer contains 8%
by weight scandium. [0131] 39. Solder alloy according to Claim 1 or
8, [0132] characterized in that [0133] the melting point reducer
contains 10% by weight scandium. [0134] 40. Solder alloy according
to Claim 1, 2 or 3, [0135] characterized in that [0136] the melting
point reducer contains 13.4% by weight zirconium. [0137] 41. Solder
alloy according to Claim 25, [0138] characterized in that [0139]
the melting point reducer contains 0.5% by weight scandium. [0140]
42. Solder alloy according to one or more of the preceding claims,
[0141] characterized in that [0142] the alloy does not contain any
chromium. [0143] 43. Solder alloy according to one or more of the
preceding claims 1 to 41, [0144] characterized in that [0145] the
solder alloy contains 4.0% by weight to <8.5% by weight
chromium, in particular, 4% by weight to <7.5% by weight. [0146]
44. Solder alloy according to one or more of the preceding claims 1
to 41, [0147] characterized in that [0148] the solder alloy
contains >10% by weight to 12.5% by weight chromium, in
particular, 11% by weight to 12.5% by weight. [0149] 45. Solder
alloy according to one or more of the preceding claims, [0150]
characterized in that [0151] the solder alloy contains cobalt in a
range of 4.0% by weight to <9% by weight, in particular, 4% by
weight to <8% by weight. [0152] 46. Solder alloy according to
one or more of the preceding claims 1 to 44, [0153] characterized
in that [0154] the solder alloy does not contain any cobalt. [0155]
47. Solder alloy according to one or more of the preceding claims,
[0156] characterized in that [0157] the solder alloy does not
contain any tungsten. [0158] 48. Solder alloy according to one or
more of the preceding claims 1 to 46, [0159] characterized in that
[0160] the solder alloy contains 1.8% by weight to <3.8% by
weight tungsten, in particular, 1.8% by weight to <2.8% by
weight. [0161] 49. Solder alloy according to one or more of the
preceding claims, [0162] characterized in that [0163] the solder
alloy contains rhenium, in particular, between 2.5% by weight to
3.0% by weight. [0164] 50. Solder alloy according to one or more of
the preceding claims, [0165] characterized in that [0166] the
solder alloy contains at least one rare earth element, in
particular, yttrium, in particular, 0.5% by weight to 2% by weight.
[0167] 51. Solder alloy according to one or more of the preceding
claims, [0168] characterized in that [0169] the solder alloy
contains hafnium, in particular, in a range of 0.5% by weight to
2.5% by weight.
[0170] Additional Explanations Concerning the Solder 10:
[0171] The solder alloy is preferably nickel-based and has the
additional constituents of chromium, cobalt and tungsten as well as
2% by weight to 22.4% by weight of a melting point reducer, which
features at least one element from the group of scandium (Sc),
aluminum (Al), titanium (Ti), zirconium (Zr) or tantalum (Ta). The
percentages of chromium are preferably 7.5% to 11% by weight and in
particular, 10% by weight. The percentages of cobalt are preferably
between 8% and 11.4% by weight and in particular, 10.4% by
weight.
[0172] The percentages of tungsten are preferably at 2.8% by weight
to 6.9% by weight and in particular, at 3.8% by weight or 5.9% by
weight. In addition, up to 1.9% by weight, in particular, 1.9% by
weight, molybdenum (Mo) can be added to the solder alloy.
Additional elements may be present, but the above listing of
nickel, chromium, cobalt, tungsten, the melting point reducer and
the optional molybdenum is preferably definitive. The solder
preferably does not contain any boron, any silicon or even any
hafnium. The additional of rhenium can also preferably be dispensed
with. Likewise, no carbon is preferably used.
[0173] The solder 10 can be connected to the substrate 4 of the
component 1, 120, 130, 155 in an isothermal or a
temperature-gradient method. A gradient method is then offered if
the substrate 4 has a directional structure, for example, a SX or
DS structure so that the solder 10 subsequently has a directional
structure. Likewise, the component 1 does not need to have a
directionally solidified structure (but a CC structure), wherein,
due to the directionally solidified structure in the repaired
location 3, a high strength of the component 1 is achieved at high
temperatures, because the directionally solidified structure of the
solder 10 in the repaired location compensates for the negative
effect of the low melting point on the mechanical strength at high
temperatures.
[0174] When fusing (isothermal method or with gradient method), an
inert gas is preferably used, in particular, argon, which reduces
the chromium vaporization from the substrate 4 at high temperatures
or a reducing gas (argon/hydrogen) is used. The solder 10 may also
be applied on a large-scale on a surface of a component 1, 120,
130, 155 in order to achieve a thickening of the substrate 4, in
particular in the case of hollow components. The solder 10 is
preferably used to fill cracks 7 or depressions 7. The table
depicts the exemplary inventive compositions HT of the solder alloy
of the solder 10 (in % by weight), wherein the remainder is
nickel.
TABLE-US-00001 Alloy Cr Co Mo W Ta Al Ti Zr Sc HT1 10 9 0 3.8 3 3 0
13.4 0 HT2 10 9 1.9 3.8 0 3 0 13.4 0 HT3 10 9 0 5.9 0 3 0 13.4 0
HT4 10 9 0 3.8 3 0 3 13.4 0 HT5 10 9 1.9 3.8 0 0 3 13.4 0 HT6 10 9
0 3.8 0 0 0 0 8 HT7 10 9 0 3.8 3 0 0 0 10 HT8 10 9 0 3.8 0 0 0 0 6
HT9 10 9 0 3.8 0 0 3 13.4 0 HT10 10 9 0 3.8 0 3 0 13.4 0 HT11 8.5
10.4 0 4.4 0 0 0 13.4 0 HT12 8.5 10.4 0 4.4 0 0 0 13.4 0.5 HT13 10
9 0 3.8 0 0 0 0 10 HT14 8.5 9 1.9 3.8 0 3 3 13.4 0 HT15 8.5 10 0
3.8 0 0 3 0 0 HT16 10 9 0 3.8 0 3 3 0 0 HT17 10 9 0 3.8 3 3 0 0 0
HT18 10 9 1.9 3.8 0 3 3 0 0.5 HT19 10 10 1.9 5.9 0 0 3 13.4 0 HT20
10 9 1.9 5.9 3 3 0 13.4 0 HT21 10 10 1.9 3.8 3 3 3 13.4 0 HT22 10 9
0 3.8 0 3 0 0 6 HT23 10 9 1.9 5.9 0 0 0 0 2 HT24 10 9 1.9 3.8 0 0 0
13.4 2 HT25 10 9 1.9 3.8 0 0 0 13.4 4 HT26 10 9 1.9 3.8 0 0 0 13.4
0 HT27 8 9 1.9 1.8 5 3.6 4.1 14 hafnium 0
[0175] The solder alloys can be preferably divided into four
segments with respect to the composition of the melting point
reducer made of Zr, Al, Ti, Ta and Sc: The first segment contains
at least zirconium, the second has at least scandium, a third
segment does not contain any zirconium and any scandium, and a
fourth segment has zirconium, aluminum, titanium, tantalum with
small percentages of scandium (up to 2% by weight).
[0176] The first segment is made either of only zirconium (Claims
1+2) or only of zirconium, aluminum, titanium and tantalum (Claims
1+4) or only of zirconium and two other elements from the group of
aluminum, titanium, tantalum (Claims 1+5) or only of zirconium with
an element from the group of aluminum, titanium, tantalum (Claims
1+6).
[0177] Using titanium, aluminum and/or zirconium is especially
advantageous, because these elements promote the formation of the
.sub.Y' phase in a nickel-based material, which improves the
mechanical high-temperature properties. In this case, one, two or
three of these three elements may be used advantageously in the
solder 10 (see HT5, HT9, HT10, HT14, HT19).
[0178] The second segment is made either only of scandium (Claims
1+7) or only of scandium, aluminum, titanium and tantalum (Claims
1+8+12+13) or only of scandium and two elements of the group of
aluminum, titanium or tantalum (Claims 1+8+12+14) or only of
scandium and one element from the group of aluminum, titanium,
tantalum (Claims 1+8+12+15).
[0179] The third segment is made of at least one element from the
group of aluminum, titanium or tantalum and does not contain any
zirconium or any scandium, wherein a first example of the third
segment with the three elements of the group of aluminum, titanium
and tantalum is described (Claims 1+17). Likewise, the melting
point reducer may contain two elements from the group of aluminum,
titanium or tantalum (Claims 1+12+18+14) or only one element from
the group of aluminum, titanium or tantalum is used (Claims
1+12+18+15).
[0180] The fourth segment is made of zirconium, small percentages
(to 2% by weight) of scandium and up to three elements from the
group of aluminum, titanium and tantalum: [0181] Zr+Sc+3 from (Al,
Ti, Ta): Claims 1+3+13+25 [0182] Zr+Sc+2 from (Al, Ti, Ta): Claims
1+3+14+25 [0183] Zr+Sc+1 from (Al, Ti, Ta): Claims 1+3+15+25
[0184] The following have been proven to be the best solder alloys
(combined claims shown together): [0185] HT1:
1+3+5+10+18+22+28+30+32+36+42 [0186] HT2:
1+3+6+18+19+22+24+27+28+30+32+35+42 [0187] HT3:
1+3+6+18+19+22+24+27+28+30+34+36+42 [0188] HT4:
1+3+5+9+18+20+21+23+28+30+32+36+42 [0189] HT5:
1+3+6+18+20+23+24+28+30+32+35+42 [0190] HT6:
1+7+8+28+30+32+36+38+42 [0191] HT7:
1+8+12+15+21+22+23+28+30+32+36+39+42 [0192] HT8:
1+7+8+28+30+32+36+7+42 [0193] HT9:
1+3+6+18+20+23+24+28+30+32+36+40+42 [0194] HT10:
1+3+6+18+19+22+24+28+30+32+36+40+42 [0195] HT11:
1+2+18+22+23+24+29+31+33+36+40+42 [0196] HT12:
1+3+22+23+24+25+29+31+33+36+40+42 [0197] HT13:
1+7+8+28+30+32+36+39+41+42
[0198] Likewise, a preferred solder alloy may not have any chromium
Likewise, preferred values for chromium may lie in the range of
4.0% by weight to less than 7.5% by weight. Another preferred range
is represented by a percentage of greater than 11% by weight to
greater than 12% by weight chromium.
[0199] No cobalt is also preferably used for the solder alloy.
[0200] A further advantageous range of values for cobalt lies in a
range from 4% by weight to less than 8% by weight.
[0201] Likewise, the solder alloy can preferably not contain any
tungsten. Values between 1.8% by weight and less than 2.8% by
weight also represent preferred values for tungsten.
[0202] Rhenium (Re) is also preferably added to the solder alloy,
in particular, in a range of 2.5% by weight to 3% by weight.
[0203] At least one, in particular, one rare earth element, in
particular, yttrium (Y), is also preferably added, and that
preferably in a range of values from 0.5% by weight to 2% by
weight.
[0204] Hafnium is also added, in particular, in a range of values
of 0.5% by weight to 2.5% by weight.
[0205] The Method and its Parameters
[0206] In the case of soldering a solder 10 in a vacuum, something
that is done frequently, when the solder 10 or the component 1,
120, 130, 155 oxidizes, because of the use of inert gases (Ar, He,
Ar/He, H.sub.2, etc.) and/or the use of a vacuum, the problem
arises of constituents of the component 1, 120, 130, 155 or of the
solder 10 vaporizing at too low a process pressure. An oxidation of
the solder 10 or of the component 1, 120, 130, 155 takes place at
too high an oxygen partial pressure p.sub.O2.
[0207] The invention method therefore proposes to conduct a
soldering method in the vacuum of a processing chamber, preferably
in a furnace at a maximum oxygen partial pressure p.sub.O2 of
3.5*10.sup.-6 mbar (=3.5*10.sup.-4 Pa). The total process pressure
is preferably a maximum of 10 mbar (=1000 Pa).
[0208] The total process pressure is preferably at least 0.035 mbar
(3.5 Pa). The oxygen partial pressure p.sub.O2 is preferably at
least 10.sup.-7 mbar (10.sup.-5 Pa).
[0209] The soldering method is particularly preferably conducted at
a maximum oxygen partial pressure p.sub.O2 of 10.sup.-6 mbar
(=10.sup.-4 Pa). The total process pressure is particularly
preferably a maximum of 1 mbar (=100 Pa). The total process
pressure is particularly preferably at least 0.1 mbar (=10 Pa). The
oxygen partial pressure p.sub.O2 is particularly preferably at
least 5*10.sup.-7 mbar (=5*10.sup.-5 Pa).
[0210] These pressure values are achieved particularly in that the
processing chamber features a vacuum in the interior and is
preferably steadily evacuated and preferably flushed with a pure
inert gas (Ar 5.0, preferably Ar 6.0). This preferably takes place
for at least 10 hours, in particular, for 48 hours with a flow rate
preferably between 0.2 l/min and 1 l/min.
[0211] In this case, preferably argon 6.0 is used (representing an
oxygen percentage of 5.times.10.sup.-7 in the process gas), which,
however, is preferably filtered through a gas cleaning cartridge so
that the content of oxygen and water is reduced by a factor of 100,
thereby achieving an oxygen percentage of 5.times.10.sup.-9 in the
process gas, which is introduced into the processing chamber.
[0212] Possible soldering methods are explained on the basis of
FIG. 1.
BRIEF DESCRIPTION OF THE DRAWINGS
[0213] FIG. 1 depicts cross-sectional views of a component during
and after a treatment with the inventive solder,
[0214] FIG. 2 perspectively depicts a turbine blade,
[0215] FIG. 3 perspectively depicts a combustion chamber,
[0216] FIG. 4 depicts a gas turbine, and
[0217] FIG. 5 depicts a list of super alloys.
DETAILED DESCRIPTION OF THE DRAWINGS
[0218] FIG. 1 depicts a component 1, which is treated with a solder
10 from an inventive solder alloy. The component 1 is comprised of
a substrate 4, which, in particular, in the case of components for
high-temperature applications, in particular, for turbine blades
120, 130 (FIG. 2) or combustion chamber elements 155 (FIG. 3) for
steam or gas turbines 100 (FIG. 4), is made of an iron-based,
nickel-based or cobalt-based super alloy. These can preferably be
the known materials PWA 1483, PWA 1484 or Rene N5 (see FIG. 5). The
solder 10 is also used in blades for aircraft.
[0219] The substrate 4 has a crack 7 or a depression 7, which is
supposed to be filled up during soldering. The cracks 7 or
depressions 7 are preferably approximately 200 .mu.m wide and can
be up to 5 mm deep. In this case, the solder 10 from the solder
alloy is applied in or in the vicinity of the depression 7 and due
to a heat treatment (+T) fuses the solder 10 below a melting
temperature of the substrate 4 and completely fills the depression
7.
[0220] FIG. 2 shows a perspective view of a blade 120 or guide
blade 130 of a turbo-machine, which extends along a longitudinal
axis 121.
[0221] The turbo-machine can be a gas turbine of an aircraft or a
power plant to generate electricity, a steam turbine or a
compressor.
[0222] Along the longitudinal axis 121, the blade 120, 130 features
in succession a fastening area 400, an adjoining blade platform 403
as well as a blade pan 406 and a blade tip 415. As the guide blade
130, the blade 130 can have another platform (not shown) on its
blade tip 415.
[0223] Formed in the fastening area 400 is a blade root 183, which
serves to fasten the rotor blades 120, 130 on a shaft or a disk
(not shown). The blade root 183 is embodied, for example, as a
hammer head. Other embodiments of a Christmas-tree root or dovetail
root are possible. The blade 120, 130 features a leading edge 409
and a trailing edge 412 for a medium, which flows past the blade
pan 406.
[0224] In the case of conventional blades 120, 130, solid metallic
materials are used, in particular, super alloys, in all areas 400,
403, 406 of the blade 120, 130. These types of super alloys are
known, for example, from EP 1 204 776 B1, EP 1 306 454, EP 1 319
729 A1, WO 99/67435 or WO 00/44949; these documents are part of the
disclosure with regard to the chemical composition of the alloy.
The blade 120, 130 in this connection may be fabricated by a
casting method, also by means of directional solidification, by a
forging method, by a milling method or combinations thereof.
[0225] In the case of conventional blades 120, 130, solid metallic
materials are used, in particular, super alloys, in all areas 400,
403, 406 of the blade 120, 130. These types of super alloys are
known, for example, from EP 1 204 776 B1, EP 1 306 454, EP 1 319
729 A1, WO 99/67435 or WO 00/44949; these documents are part of the
disclosure with regard to the chemical composition of the alloy.
The blade 120, 130 in this connection may be fabricated by a
casting method, also by means of directional solidification, by a
forging method, by a milling method or combinations thereof.
[0226] Fabricating these types of monocrystalline work pieces is
accomplished, for example, by directional solidification from the
melt. In this case, this is a casting method, in which the liquid
metallic alloy is solidified into a monocrystalline structure,
i.e., into a monocrystalline work piece, or directionally
solidified.
[0227] In the process, dendritic crystals are aligned along the
thermal flow and form either a column-crystalline grain structure
(columnar, i.e., grains that run over the entire length of the work
piece and, in this case, according to general language usage, are
described as directionally solidified) or a monocrystalline
structure, i.e., the entire work piece is comprised of a single
crystal. With this method, the transition to globulitic
(polycrystalline) solidification must be avoided, because
transverse and longitudinal grain boundaries necessarily form
through undirected growth, which undo the good properties of the
directionally solidified or monocrystalline component.
[0228] If the subject consists of directionally solidified
structures in general, what is meant is both monocrystals, which do
not have any grain boundaries or at most small-angle grain
boundaries, as well as column-crystalline structures, which have
grain boundaries running possibly in the longitudinal direction,
but not any transverse grain boundaries. In terms of the latter
crystalline structures, one speaks of directionally solidified
structures. These types of methods are known as U.S. Pat. No.
6,024,792 and European Patent Document No. EP 0 892 090 A1; these
documents are part of the disclosure with respect to the
solidification method.
[0229] The blades 120, 130 may likewise feature coatings against
corrosion or oxidation, e.g., (MCrAlX; M is at least one element
from the group of iron (Fe), cobalt (Co), nickel (Ni); X is an
active element and stands for yttrium (Y) and/or silicon and/or at
least one element from the rare earths, or hafnium (Hf)). These
types of alloys are known as EP 0 486 489 B1, EP 0 786 017 B1, EP 0
412 397 B1 or EP 1 306 454 A1. The density is preferably 95% of the
theoretic density. A protective aluminum oxide layer (TGO=thermal
grown oxide layer) forms on the MCrAlX layer (as an intermediate
layer or as the outermost layer).
[0230] The layer composition preferably features
Co-30Ni-28Cr-8A1-0, 6Y-0, 7Si or Co-28Ni-24Cr-10Al-0, 6Y. In
addition to these cobalt-based protective coatings, nickel-based
protective layers are also preferably used, such as Ni-10Cr-12Al-0,
6Y-3Re or Ni-12Co-21Cr-11Al-0, 4Y-2Re or Ni-25Co-17Cr-10Al-0, 4Y-l,
5Re.
[0231] A thermal barrier coating can be present on the MCrAlX,
which is preferably the outermost layer, and is made, for example,
of ZrO.sub.2, Y.sub.2O.sub.3--ZrO.sub.2, i.e., it is not partially
or completely stabilized by yttrium oxide and/or calcium oxide
and/or magnesium oxide. The thermal barrier coating covers the
entire MCrAlX layer. Columnar grains are formed in the thermal
barrier coating by using suitable coating methods such as, for
example, electron-beam physical vapor deposition (EB-PVD). Other
coating methods are conceivable, for example, atmospheric plasma
spraying (APS), LPPS, VPS or CVD. The thermal barrier coating can
have porous, microcrack or macrocrack-afflicted grains for better
resistance to thermal shock. The thermal barrier coating is
preferably more porous than the MCrAlX layer.
[0232] Refurbishment means that components 120, 130 must possibly
be freed of their protective layers after use (e.g., by sand
blasting). Afterwards, the corrosion and/or oxidation layers or
products are removed. As the case may be, any cracks in the
component 120, 130 are also repaired. Then the component 120, 130
is recoated and the component 120, 130 is reused.
[0233] The blade 120, 130 can be embodied to be hollow or solid. If
the blade 120, 130 is supposed to be cooled, it is hollow and, as
the case may be, has film cooling holes 418 (shown with dashed
lines).
[0234] FIG. 3 depicts a combustion chamber 110 of a gas turbine.
The combustion chamber 110 is embodied, for example, as a so-called
annular combustion chamber, in which a plurality of burners 107
arranged in the circumferential direction around a rotational axis
102 lead into a common combustion chamber area 154, and generate
the flames 156. To this end, the combustion chamber 110 is embodied
as whole, as an annular structure, which is positioned around the
rotational axis 102.
[0235] To achieve a comparatively high degree of efficiency, the
combustion chamber 110 is designed for a comparatively high
temperature of the working medium M of approximately 1000.degree.
C. to 1600.degree. C. In order to also make a comparatively long
operating duration possible, in the case of these operating
parameters which are unfavorable for the materials, the combustion
chamber wall 153 is provided on its side facing the working medium
M with an inner lining formed from heat shield elements 155. Every
heat shield element 155 made of an alloy is equipped on the
working-medium-side with an especially heat-resistant protective
layer (MCrAlX layer and/or ceramic coating) or is fabricated from
high-temperature resistant material (solid ceramic stones). These
protective layers can be similar to the turbine blades, i.e., for
example, MCrAlX means: M is at least one element from the group of
iron (Fe), cobalt (Co), nickel (Ni), X is an active element and
stands for yttrium (Y) and/or silicon and/or at least one element
from the rare earths, or hafnium (Hf). Such alloys are known as EP
0 486 489 B1, EP 0 786 017 B1, EP 0 412 397 B1 or EP 1 306 454
A1.
[0236] A ceramic thermal barrier coating can be present on the
MCrAlX and is made, for example, of ZrO.sub.2,
Y.sub.2O.sub.3--ZrO.sub.2, i.e., it is not partially or completely
stabilized by yttrium oxide and/or calcium oxide and/or magnesium
oxide. Columnar grains are formed in the thermal barrier coating by
using suitable coating methods such as, for example, electron-beam
physical vapor deposition (EB-PVD). Other coating methods are
conceivable, for example, atmospheric plasma spraying (APS), LPPS,
VPS or CVD. The thermal barrier coating can have porous, microcrack
or macrocrack-afflicted grains for better resistance to thermal
shock.
[0237] Refurbishment means that heat shield elements 155 must
possibly be freed of their protective layers after use (e.g., by
sand blasting). Afterwards, the corrosion and/or oxidation layers
or products are removed. As the case may be, any cracks in the heat
shield element 155 are also repaired. Then the heat shield elements
155 are recoated and the heat shield elements 155 are reused.
[0238] Because of the high temperatures inside the combustion
chamber 110, a cooling system can also be provided for the heat
shield elements 155 or for their retaining elements. The heat
shield elements 155 are then hollow, for example, and, as the case
may be, have cooling holes (not shown) leading into the combustion
chamber area 154.
[0239] FIG. 4 depicts an example of a gas turbine 100 in a
longitudinal partial section. In its interior, the gas turbine 100
has a rotor 103 rotatably mounted around a rotational axis 102 with
a shaft 101, and is also designated as a turbine rotor. Following
in succession along the rotor 103 are an intake housing 104, a
compressor 105, for example, a torus-like combustion chamber 110,
in particular, an annular combustion chamber, with several
coaxially arranged burners 107, a turbine 108 and the exhaust gas
housing 109. The annular combustion chamber 110 communicates with,
for example, an annular, hot-gas channel 111. Four series connected
turbine stages 112 form the turbine 108 there, for example. Every
turbine stage 112 is formed, for example, from two blade rings.
Viewed in the flow direction of a working medium 113, a row 125
formed of rotor blades 120 follows in the hot-gas channel 111 of a
guide blade row 115.
[0240] The guide blades 130, in this case, are fastened in an
internal housing 138 of a stator 143, whereas the rotor blades 120
of a row 125 are attached to the rotor 103 by means of a turbine
disk 133, for example. Coupled to the rotor 103 is a generator or a
work machine (not shown).
[0241] During operation of the gas turbine 100, air 135 is
suctioned by the compressor 105 through the intake housing 104 and
compressed. The compressed air made available on the turbine-side
end of the compressor 105 is conveyed to the burners 107 and mixed
there with a combustion means. The mixture is then burned in the
combustion chamber 110 with the formation of the working medium
113. From there, the working medium 113 flows along the hot-gas
channel 111 past the guide blades 130 and the rotor blades 120. At
the rotor blades 120, the working medium 113 expands transmitting
an impulse so that the rotor blades 120 drive the rotor 103 and
this drives the work machine coupled therewith.
[0242] The components exposed to the hot working medium 113 are
subject to thermal stress during operation of the gas turbine 100.
The guide blades 130 and rotor blades 120 of the first turbine
stage 112, as viewed in the flow direction of the working medium
113, are subject to the most thermal stress besides the heat shield
elements lining the annular combustion chamber 110. In order to
withstand the temperatures prevailing there, they can be cooled
with a cooling medium. Likewise, the substrates of the components
may have a directionally solidified structure, i.e., they are
monocrystalline (SX structure) or have only longitudinal oriented
grains (DS structure). For example, iron-based, nickel-based or
cobalt-based super alloys are used as the material for the
components, in particular, for the turbine blades 120, 130 and
components of the combustion chamber 110. These types of super
alloys are known, for example, as EP 1 204 776 B1, EP 1 306 454, EP
1 319 729 Al, WO 99/67435 or WO 00/44949.
[0243] Likewise, the blades 120, 130 may have coatings against
corrosion (MCrAlX; M is at least one element from the group of iron
(Fe), cobalt (Co), nickel (Ni), X is an active element and stands
for yttrium (Y) and/or silicon, scandium (Sc) and/or at least one
element from the rare earths or hafnium). These types of alloys are
known as EP 0 486 489 B1, EP 0 786 017 B1, EP 0 412 397 B1 or EP 1
306 454 A1, which are part of this disclosure with respect to the
chemical composition.
[0244] A thermal barrier coating may be present on the MCrAlX, and
is made, for example, of ZrO.sub.2, Y.sub.2O.sub.3--ZrO.sub.2,
i.e., it is not partially or completely stabilized by yttrium oxide
and/or calcium oxide and/or magnesium oxide. Columnar grains are
formed in the thermal barrier coating by using suitable coating
methods such as, for example, electron-beam physical vapor
deposition (EB-PVD).
[0245] The guide blade 130 has a guide blade root (not shown here)
facing the internal housing 138 of the turbine 108 and a guide
blade head opposite from the guide blade root. The guide blade head
is facing the rotor 103 and fixed on a fastening ring 140 of the
stator 143.
* * * * *